Thought experiment of workout plans

This thought experiment would be about making use of your time on exercising. Should there be a structure to your workout plan? Or, in other words, should you make a workout plan at all. I think the best way to answer this is to answer the question, why are you working out? My concise answer to that is, I workout because I would like to be able to do the things I have never been able to do before physically, that I want to be able to do. Examples are muscle ups, front lever, planche, climb walls effortlessly, etc. I'm 42 now, and I never would have thought I would have a love for working out. The reason I like it now is the fact that I conditioned my mind to like looking at videos of people being able to do seeming impossible feats of physical strength. So, my short answer is I don't really need to make a plan. I just do what comes to mind for the day, that keeps me motivated. How do you see working out as?